Transmission trouble?

[ROX]

Hi, I would like any thoughts you might have on a problem I've noticed with my 2005 H2.

Lately, when I get in the car in the morning, I've noticed that right after I start it, the driveline jerks. I think it's getting worse.
This morning I started the car, and it jerked backward. (It scared me!) I only notice it after it's been sitting all night. I have been backing into our shop to park (flat, level floor) and I noticed it 4 or 5 times now in the past couple of weeks. The last gear it's in before I put it in park is reverse.
Also, I'm noticing that at a stop light, or after slowing down almost to a stop, when I give it gas to get moving it will act underpowered and then jerk forward. Like it's not quite in the right gear.

I'm going to tell the dealership because it's still under the Manufacturer's Warranty, but I was hoping to get some info before I go in. I'm headed to Moab at the end of next week.

Any thoughts on this from you folks?